 197 ENDO (Lond Engl) 2018;12(3):197–204 REVIEW James L. Gutmann, DDS, Cert Endo, PhD, FACD, FICD, FADI, FAAHD, FDSRCSEd Texas A&M University College of Dentistry, Dallas, Texas, USA Vivian Manjarres DDS, Cert Endo, FAAHD Department of Endodontics, Nova Southeastern College of Dental Medicine, Davie, Florida, USA Correspondence to: James L. Gutmann, 3212 Basil Court, Dallas, Texas 75204-5543, USA E-mail: jlg@histden.org James L. Gutmann, Vivian Manjarres Origins and perspectives on the use of cold in dentistry with a particular focus on its use in diagnosis Key words cold test, dental pulp, diagnostic testing, pulpitis, vitality Contemporarily, most clinicians use the cold test on teeth suspected to have pulpitis. The origins of this diagnostic technique are vague, as is the pathophysiological interpretation of the patient’s responses. Correlations are varied relative to the status of the pulp tissue. There are numerous ques- tions regarding this diagnostic approach, many of which remain unanswered. Was this diagnostic test chosen based on the patient’s signs and symptoms? Did it offer a direct and accurate picture of the status of the dental pulp? Could it take into account the presence of large amounts of reparative dentine that may have formed in the tooth in question? Was it accurate in the presence of the tooth that displayed a periapical lesion … or was it even necessary in these cases? This paper addresses both the history of the use of cold in dentistry and some of the proposed origins and constraints of this technique for pulpal diagnosis, along with clinical and scientific perspectives.  Introduction The use of cold applied to teeth during contem- porary pulpal diagnostic testing procedures is the prime modus operandi for determining the accuracy of the pulpal status 1-6 , especially in the presence of a suspected pulpitis. Moreover, if the patient com- plains of cold sensitivity or pain, the application of a cold stimuli is likely to be the first and possibly the only test used by the clinician. Many publications have addressed the physio- logical and clinical aspects of this test 1-6,7 . When the patient responds abnormally, or sometimes even with a highly sensitive response to the stimulus, the clinician will automatically assume the presence of a pulpitis. When there is no response, a conclusion of non-vitality is often accepted. However, many teeth respond somewhere in between these two arbitrary parameters, causing the clinician to make a judge- ment call as to the status of the pulp without any direct correlation of the test response to the histo- pathological status of the pulp. Often the decision may be influenced by extraneous factors on the part of both the clinician and the patient. Intimately associated with the use of cold testing are the concepts of vitality and non-vitality 3,8,9 , as all of the publications that address this issue will claim. Some will use more contemporary concepts such as sensibil- ity testing 4,10,11 , and others will use sensitivity test- ing 2,8 . Somewhat removed from these categories are the concepts of a normal response, versus an abnormal response, versus no response, and versus a variable but not clearly defined response, and these influence the “judgement call” on the part of the clinician. This clearly implies that multiple test parameters must be used for a more accurate pulpal assessment 3-5,9 . However, none of these concepts focuses on a very real issue that must be considered, which is whether the cold test really determines the vitality of the pulp tissue, as opposed to determining the true health or sickness of the dental pulp. This distinction is especially necessary in the contemporary concept of pulp preservation 12 and the use of techniques to retain a pulp that can repair itself 13-20 .